Process of separating sulfonic acids.



UNITED STATES FFICE.

LUDWIG oTTo I-IELMERS, or HAMBURG, GERMANY, ASSIGNOR TO IonTHYoL- GESELLSCHAFT oosons, HERMANNI & 00., or HAMBURG, GERMANY.

PROCESS OF SEPARATING SULFONIC ACIDS.

srEcIFIcATIoN formingpart of Letters Patent No. 709,321, dated September 16, 1902.

i I Application filed August 30, 1901. Serial No. 73,863. p specimens.)

To all whom it-7nay concerns I l y Be it known that LILUDWIG OTTo IIELMERs,

a subject of the German Emperor, and a resident of Hamburgyin the German Empire,.

such as, for example, ichthyol sulfonic acidalso solutions of theinorganic salts of these .sulfonic acids are treated with a solution of an alkaloid oralkaloidal salt, it yields a precipitate which consists of the alkaloid salt of such sulfonic acid." (See Harold Wyatt, The Chemist rind Druggt'st, December, 1895, and Karl Ullmann, Aerztl'icher C'entrdZ-Anzez'ger, 1893, Nos. 5 and 6.) Careful experiments have shown that notonly alkaloids, but also other organic"basessuch as anilin, piperi are formed soluble saltS-thatis to say, salts No. 671,135, dated April 2, 1901,. 3.5

which after the reaction remain dissolved in the solution. The organic bases therefore exhibit a similar behavior as that described with reference to the alkaline-earth and heavy metal salts of these sulfonic acids in the specification of the United States Patent Therefore the neutralization of these sulfonic acids with organic bases renders it possible to produce, likewise, a separation of these acids into acids rich in sulfur and giving salts readily soluble in water and into acids poor in sulfur and giving salts mostly insoluble in water quite analogous to the processes described in the specification of the aforementioned patent. Again, in these salts with organic bases the I proportion soluble in Water is dependent upon the nature of the base used. As, for

. example, the proportion of lime salts soluble mixture sulfonic acids of higher or lower per centage of sulfur.

The following examples may serve to eX- plain the process:

First. One kilogram of the sulfonized prod: not obtained by the reaction of concentrated sulfuric acid upon Seefeld oil and which has been freed from any free sulfuric acid is dis solved in four liters of water. This solution is treated with about three hundred grams of anilin suspended in water,and the superfluous anilin is then removed by blowing steaminto the mixture. After some time a dark-brown deposit is formed at the bottom of the vessel. The yellowish-brown liquid above the said precipitate is decanted and evaporated. The

residue thus obtained after completely drying is a brown yellow hygroscopic powder having little odor anda peculiar flavor. The analysis of this salt gives a proportion of twenty-nine per cent. of anilin and 15.7 per cent. of sulfur. Thus the acid contains 22.2 per cent. of sulfur. The precipitate at the bottom of the vessel which has been formed by the addition of anilin to the sulfonized product is, as far as possible, freed from any remaining liquid and then dried. Thus a brown readily-pulverizable substance which is nearly insoluble in water is obtained. In this substance the proportions of anilin are found to be 13.5 per cent. and those of sulfur to be 14.3 per cent. From this is calculated the proportion of sulfur to be 16.5 per cent. for the part combined with aniliu of the sulfonized product.

Second. A twenty-per-cent. aqueous solution of the sulfonized product mentioned in the example No. 1 is neutralized under heat with piperazin. After some time the liquid is decanted off from the precipitate and evaporated. The soluble piperazin salt obtained from the dried residue formsa yellowish pow- .der containing seventeen per cent. of piperazin (C H N and nineteen'per cent. of sulfur. In the acid is therefore contained twenty-three per cent. of sulfur. The in-,

soluble salt obtained in the form of a prestance is fonnd seven per cent. of piperazin ,lighter color than the insoluble salts.

which are'also soluble in water.

solved.

nated with sodium sulfate, which may be easily removed by suitable means, such as by dissolving the anilin salt in alcohol.

The salts soluble in water of the sulfonic acids with organic bases, are generally of They are mostly soluble in alcohol and glycerin and insoluble inether and benzol. Their watery solutions produce no precipitates with the salts of alkalin earths and heavy metals, as

the sulfonic acids obtained from these solu ble salts of the organic bases form with alkaline-earth and heavy metal salts likewise salts These salts, as also the acids, are entirely like the compounds described in the specifications of the United States Patent No. 671,135, aforesaid, and pending application, Serial No. 729,355, filed September 2, 1899. The salts of the organic bases insoluble in water dissolve in rather large quantity in watery solutions of the sulfonic acids and their salts and also in solutions of the free organic bases. In alcohol the salts generally are vcrylittle dissolved. A larger portion can be dissolved in benzol,while in chloroform they are almost completely dis- Ether and petroleum-ether extract from the insoluble salts a neutral reacting oil, the so-called su1fon when a sulfonic acid containing sulfon is used for the production of the salt. The insoluble salts are decomposed bymeans of mineral acids. It, for example, the precipitate is heated with muriatic acid, the base is dissolved as muriate, while the sulfonic acid remains at first undissolved, but

version of the acids into their alkaline-earth and heavy metal salts, as owing to the facility of separating the organic base it is not difficult to obtain from the insoluble salts the free acids'or alkaline salts of these, sulfonic acids being poor in sulfur, whereas the insoluble alkaline-earth and heavy metal salts can I only be converted into their alkaline salts after prolonged heating and mostly under partial decomposition.

Having fully described my invention, What I claim, and desire to secure'by Letters Patout, is-

The process of separating sulfonic acids into compounds rich in sulfuran'd compounds poor in sulfur, which consists in converting f the sulfonized products obtained by the action of sulfuric acid upon sulfureted hydrocarbons into salts of organic bases and separating the portions of the salts thus obtained which are soluble in water from the insoluble portions, substantially as and for the purpose set forth.

, LUDWIG OTTO HELMERS. Witnesses: ALEXANDER SPECHT, E. H. L. MUMMENHOFF. 

